Hello,I do real estate flips currently under my own name (I know lots of liability risk), but the up side is I pay capital gains tax at a lower rate then a pass through LLC.Can I create an LLC that has no income, so that I can contribute to a 401(k)?

If you want to avoid double taxation, you need to make certain that you have an entity recognized by the CRA as flow through. 

Furthermore, you are also a realtor.You should reach out to an accountant who is familiar with real estate taxation. 

They consider you to have “taken out profit already” since the 1031 delays the taxation of that profit if you reinvest all the proceeds (and just “took the profit out with a refi”).

@Subbie Kaur: Thanks for your input and my strategy is to buy low and sell High, with that said I am in the beginning stages of investing and have a limited knowledge of the inner workings of Taxation Corporation structure so on and so on and I'm sure there will be some bumps along the way but to make a long story short my strategy is simple to make money honestly and legally regardless the end of the day make money

Any assessed value above the agricultural assessment is exempt from real property taxation. “ tells me nothing.

Flipping is a business, and when a tax-exempt entity engages in a business on a regular or repeated basis, then taxation known as UBIT applies. 

I hear we are taxed twice (UK accountant) but I see we there is a double taxation clause in place.

@Nathan FeronThere are a couple of CPA's/Accounants who are in New York that are familiar with NJ Taxation and may be able to help. 

LTV will be a bit lower than you may get in a personally guaranteed loan, so be sure to speak with some lenders like North American Savings Bank or First Western Federal Savings early in your strategy planning.The IRA can then use that new liquidity to make other investments such as purchasing another property, being a hard money lender, etc.The use of debt-financing within an IRA does expose the IRA to taxation on Unrelated Debt-Financed Income (UDFI).